Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2024 February 9 [2]See Explanation. Clicking on the picture will download the highest resolution version available. When Roses Aren't Red Image Credit & [3]Copyright: [4]Tommy Lease (Denver Astronomical Society) Explanation: Not all roses are red [5]of course, but they can still be very pretty. Likewise, the beautiful [6]Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue, in part because the dominant emission in the nebula is [7]from hydrogen atoms. Hydrogen's strongest optical emission line, known as H-alpha, is in the red region of the spectrum. But the beauty of an emission nebula need not be appreciated in red light alone. Other atoms in the nebula are also excited by energetic starlight and produce narrow emission lines as well. [8]In this close-up view of the Rosette Nebula, narrowband images are mapped into broadband colors to show emission from Sulfur atoms in red, Hydrogen in green, and Oxygen in blue. In fact, the [9]scheme of mapping these narrow atomic emission lines (SHO) into the broader colors (RGB) is adopted in many [10]Hubble images of emission nebulae. This image spans about 50 light-years across the center of the [11]Rosette Nebula. The nebula lies some 3,000 [12]light-years away in the constellation Monoceros. Tomorrow's picture: ingenuity __________________________________________________________________ [13]< | [14]Archive | [15]Submissions | [16]Index | [17]Search | [18]Calendar | [19]RSS | [20]Education | [21]About APOD | [22]Discuss | [23]> __________________________________________________________________ Authors & editors: [24]Robert Nemiroff ([25]MTU) & [26]Jerry Bonnell ([27]UMCP) NASA Official: Amber Straughn [28]Specific rights apply. [29]NASA Web Privacy Policy and Important Notices A service of: [30]ASD at [31]NASA / [32]GSFC, [33]NASA Science Activation & [34]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2402/Rosette2024newt533mmcopy.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.instagram.com/colorado_astro/ 5. https://en.wikipedia.org/wiki/Roses_Are_Red 6. http://www.atlasoftheuniverse.com/nebulae/ngc2237.html 7. https://en.wikipedia.org/wiki/H-alpha 8. https://www.astrobin.com/net448/ 9. https://aaa.org/2020/06/23/pillars-of-creation-using-the-hubble-palette/ 10. https://hubblesite.org/home 11. http://www.messier.seds.org/xtra/ngc/n2244.html 12. http://www.atlasoftheuniverse.com/5000lys.html 13. https://apod.nasa.gov/apod/ap240208.html 14. https://apod.nasa.gov/apod/archivepix.html 15. https://apod.nasa.gov/apod/lib/apsubmit2015.html 16. https://apod.nasa.gov/apod/lib/aptree.html 17. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 18. https://apod.nasa.gov/apod/calendar/allyears.html 19. https://apod.nasa.gov/apod.rss 20. https://apod.nasa.gov/apod/lib/edlinks.html 21. https://apod.nasa.gov/apod/lib/about_apod.html 22. http://asterisk.apod.com/discuss_apod.php?date=240209 23. https://apod.nasa.gov/apod/ap240210.html 24. http://www.phy.mtu.edu/faculty/Nemiroff.html 25. http://www.phy.mtu.edu/ 26. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 27. http://www.astro.umd.edu/ 28. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 29. https://www.nasa.gov/about/highlights/HP_Privacy.html 30. https://astrophysics.gsfc.nasa.gov/ 31. https://www.nasa.gov/ 32. https://www.nasa.gov/centers/goddard/ 33. https://science.nasa.gov/learners 34. http://www.mtu.edu/